Dynamoelectric machine



March 16, 1954 M. R. KRASNO DYNAMOELECTRIC MACHINE 2 Sheds-Sheet 1 Filed March 25, 1952 Inventor Mam/M A? /fl-aJ/70 Attorng March 16, 1954 KRASNO 2,672,564

DYNAMOELECTRIC MACHINE Filed March 25, 1952 2 Sheets-Sheet 2 bzventor Nam/6W A? Ma /20 Attorney Patented Mar. 16, 1954 Maxwell R. Kr-asno, Waukesha, Wis., assignor to Raytheon Manufacturing Company, a corporation of Delaware Application March'25, 1952, Serial No. 278,446

12 Claims. l

The present invention relates in :general to a dynamo-electric machine, "and more particularly 213012, dynamo-electric machine wherein :a member thereof is used both as a .pole piece and 3.8 13

commutator.

in the manufacture :of motors :or generators, there is-an apparent need for a small, simple and low cost direct current unit. To achieve these ends, it .is necessary that a-unlt have the same part perform more than one function.

ilccordingly, an important object :of the present invention is to provide a dynamo-"electric machine that requires a minimum :number of parts by providing a member therein that .is used'both as a pole piece and as :a commutator.

Another object of the present invention .is to provide :a small compact dynamo-electric machine by providing an insulated pole piece-com niutator member :of :a suitable magnetic material connected to an armature winding and having an extension portion thereof plated with suitable conducting material to provide commutation and :a :flux path.

'Other objects and features will appear upon iurther perusal of :the detailed description taken in conjunction with the accompanying drawing in which:

Figure 1 is :a side .elevational view 10f ithe dynamic-electric machine :of the present invention with :a portion thereof in section to 'i'llustratethe internal construction thereof;

Figure 2 is a perspective View of the pole piece-ecommuta'tor member;

Figure 3 is a perspective view of two pole piece-commutator members having the extension :portions thereof intermeshing;

Figure A is a perspective view of the dynamoelectric machine embodying the present invention and illustrating the electrical connections therewith for use as a motor;

Figure 5 is a schematic diagram illustrating a conventional electrical circuit the present. invention as argenerator;

Figure 6 is a side view of the field magnet structure.

.Briefly described, a dynamo-electric machine .is provided havinga suitable'armature-shaft. A suitable core surrounds -.a portion of the armature shaft to carry the magnetic from pole to ,pole. In the preferred embodiment, the

-;armature core an electrically insulated powdared iron core. The core-may also be :a or laminated core that is suitably insulated-elem trical-ly from [either or both pole :pieces by an air gap or other suitable means. Surrounding the armature core is a suitable armature coil which may be a single coil armature wound either scramble, layer or universal. ":Eor providing electrical connections between the receiv ting assembly and an external conventional brushes or stationary exterior members are provided. The armature structure, in the preferred embodiment, is suitably mounted inside of a hollow cylindricalfieldmagnot structure having the interior surface thereof magnetized. The field magnetic structure is .made of any'sui-table material, such use. single ring of Alnico, -.or a number of permanent magnets suitably arranged.

According to the invention, for providing a pole piece and commutator, a member attached to the armature shaft and encompasses the armature coil. The pole piece-commutator member is made of any suitable .material, .-.s11ch as soft iron, to enable it to function as 'a pole piece. In addition thereto, an extension portion thereof providesa surface for engaging the brushes. The brush engaging surface :is plated or sprayed with copper or other suitable conducting material in order to provide :acommutator contact surface. 7

In the preferred embodiment, the pole piececommutator member is an annular member having the extending portions thereof substantially parallel .to the armature shaft. Two similar pole piece-commutator members are intermeshed to provide an annular encased unit wherein the base portions of the pole piece-commutator members form parallel sides and the extended portions upon intermeshi-ng :form an enclosed annular portion. It is to :be noted that the pole piece-commutator members are insulated from one another by suitable means, such as plastic, mica or air gaps. One pole piecewommutator member :is electrically connected to one end of the armature coil, "while the other pole piece-commutator member is electrically connected to the other end of thearmature coil. the preterred embodiment, to :provide the insulation, after the shaft, score, windthe, and pole piece-commutator .members are 'assembled, .zth'e components are :hnpressnat'ed plastic, which also functions as a cohesive agent.

Referring now to Figure 1 for a more detailed description, a dynamo-electric machine 1H] herein provided having an armature assembly I I anda stator assembly 132..

The armature assembly I l comprises a suitable armature shaft :sl3 having :a gear wheel I4 i-thereon. The :gear 1:4 zprovides a driving mechanism, when the :unit is coupled to another mechanism.

Attached to the rotatable armature shaft :1 3 to provide a flux path is a suitable armature core 15. The armature core :15 rotates with the armature I3 and in the preferred embodiment :is insulated powdered core. The :core 4 .5 may he a solid or a laminated core, and.

do: etectrically .insuleteditrom emperor truth pole I pieces by any suitable means, such as plastic or mica.

For providing armature windings or means subject to a magnetic field, an armature winding or coil I6 is herein provided which is wound around core I5. The coil I6 may be a simple single coil winding, wound either scramble, layer or universal. One of the advantages of the present invention over other direct current units is that the structure herein provided enables the use of only one coil that may be of any type that is easy to wind.

For providing a permanent magnetic field, the stator assembly I2 comprises suitable means, such as hollow cylindrical field magnet I1 having the internal surface thereof magnetized in a manner similar to that shown in Figure 6. The hollow cylindrical magnet I1, which may be made of any suitable magnetic material, encompasses the rotatable armature assembly I I. In lieu of a permanent magnet it is to be noted that suitable field windings may be provided which may be either series, compound, or shunt wound field coils.

In order to provide electrical connections be- According to the invention, a pole piece-com- 2 mutator structure 20 is provided for performing two functions, namely: to provide a pole piece and in addition thereto to provide a commutator.

Referring now to Figures 2 and 3, the pole piece-commutator structure comprises two similar pole piece-commutator members 2| and 22 made of suitable magnetic material, such as soft iron, to perform the function of a pole piece. In the preferred embodiment, pole piece-commutator members 2| and 22 are annularly shaped and have flat base portions 2|c and 22a, respectively. The spaced parallel portions 2|c and 2211 are provided with apertures 2 lb and 22b, respectively, for suitably receiving the armature shaft I3 for mounting thereto. The pole piece-commutator members 2| and 22 are provided with integrally formed extension portions 2|c and 220, respectively, for engaging the brushes. The brush engaging extension portions 2|c and 220 are sub stantially parallel to the armature shaft I3 and intermesh with one another to form an annular encased unit with the flat portions 2Ia and 22a forming spaced parallel side portions.

For providing brush contacting surfaces 2Id and 22d, the extension portions 2| c and 220 of the pole piece-commutator members 2| and 22 are suitably plated or sprayed with suitable material, such as copper, silver, gold, etc. In

order that the pole piece-commutator members 2| and 22 be insulated from one another, so as to enable commutation, suitable insulating material 23, such as plastic or mica is positioned therebetween.

It is to be noted that when plastic insulation is desired, the armature structure II, after the 'gear shaft I3, armature core I5, armature winding I6 and the pole piece-commutator members 2| and 22 are assembled, is impregnated with plastic and the plastic also acts as a cohesive agent, binding all these components into one solid cylindrical unit.

,-For establishing the electrical connections between the armature coil I6 and the pole piece- .cor nmutator members 2| and 22, one end of the armature winding I6 is received through an aperture 24 in the base portion 2Ia of the pole piececommutator member 2| and is connected thereto by suitable means. The other end of the armature winding I6 is received through an aperture 24 in the base portion 22a of the pole piececommutator member 22 and is connected thereto by suitable means.

Noteworthy are the advantages gained by the present invention. The simplicity of structure is its chief advantage over usual small direct current designs. Thus, only one coil is used in lieu of three or more and this coil is of the type that is easy to wind. In lieu of a large number of lamina in the pole piece structure in addition to a number of separate commutator bars, the pole piece-commutator structure of the present invention comprises only two similar stamped members.

Referring now to Figure 4, the dynamo-electric machine II] is connected to the external circuit I8 to provide a direct current motor. A suitable starting switch 25 is serially connected to a suitable direct current source of energy, such as battery 26.. serially connected to the battery 26 and the switch 25 are the brushes I9. The brushes I9 engage the pole piece-commutator members 2| and 22 by means of the plated surfaces 2Id and 22d on the integrally formed extension portions 2|c and 220, respectively. The pole piece-commutator members 2| and 22 are connected to the armature coil I6 in a manner previously described.

In operation, the starting switch 25 is closed to energize the armature coil I6 over the following path: battery 25, brushes I9, copper plated surfaces ZId and 22d, pole piece-commutator members 2| and 22, and the armature coil I6. The magnetic field produced by the current flow in the coil I6 in conjunction with the magnetic field I1 produces a torque to rotate the armature shaft I3, thus providing a motor action.

Referring now to Figure 5, which schematically illustrates the generator action. The load is shown by the resistor 21 in an external circuit 28. The resistor 21 is suitably connected to the brushes I9. In operation, conventional means are provided to impart rotation to the armature shaft I3 through the gear Wheel I4. The rotation of the armature induces an electromotive force in the armature coil I6. The current flowing through the coil I6 is rectified by the pole piececommutator members 2| and 22. The circuitry is completed through the brushes I9 to the conductors of the external circuit 28. to provide electrical energy to. the load 21.

' It is to be understood that variations and modifications may be effected without departing from the scope of the appended claims.

Iclaim:

1. In an armature assembly, a shaft for rotating said assembly, an armature winding in said assembly mounted on said shaft and rotatable therewith for providing a flux reaction, a core on said shaft encompassed by said armature winding for providing a flux path, and an insulated pole piece-commutator member encompassin said armature winding for providin a flux path and connected to said armature winding to provide commutation for said assembly.

therewith for providing a fiux reaction for said assembly, and an insulated pole piece-commutator member encompassing said armature winding for providing .a fiux path and connect d to said armature winding to provide commutation.

3. An armature assembly comprising, a shaft for rotating said assembly, an armature winding in said assembly mounted on said shaft and rotatable therewith for providing a fiux reaction, a core on said shaft encompassed by said armature winding for providing a fiux path, and a plurality of insulated pole piece-commutator members encompassing said armature winding for providing a flux path and connected to said armature windin to provide commutation for said assembly.

4. In a dynamo-electric machine, a field structure, an armature assembly, an armature winding in said armature assembly subject to the field produced by said field magnet structure, and an insulated pole piece-commutator member in said armature assembly providing a flux path for said armature assembly and connected to said armature winding for providing commutation.

5. In a dynamo-electric machine, a field magnet structure, a winding in said field magnet structure subject to the field produced by said field magnet structure, a stationary member for extending a connection from said armature assembly, and an insulated pole piece-commutator member in said assembly providing a fiux path, connected to said winding for providin commutation and contacting said stationary member for extending a connection from said armature assembly.

6. In a dynamo-electric machine, a field magnet structure, an armature assembly, an armature winding in said armature assembly subject to the field produced by said field magnet structure, and a plurality of insulated pole piece-commutator members in said armature assembly providing a flux path for said armature winding and connected to said armature windin for providing commutation.

7. In a dynamo-electric machine, a field ma net structure, an armature assembly, a winding in said armature assembly subject to the field .produced by said field magnet structure, a brush for extending a connection from said armature assembly, an insulated pole piece-commutator member in said armature assembly providing a fiux path for said winding and connected to said winding for providing .commutation, and a conducting surface on said pole piece-commutator member providing a contact surface for engaging said brush.

8. In a dynamo-electric machine, a field magnet structure, an armature assembly, a winding in said armature assembly subject to the field produced by said field magnet structure, stationary members for extending a connection from said armature assembly, a plurality of insulated pole piece-commutator members in said armature assembly providing a flux path for said armature assembly and connected to said winding for providing commutation, and a plurality of plated conducting surfaces on said pole piececommutator members engaging said stationary members for providing a contacting surface therewith.

9. In a dynamo-electric machine, a field ma net structure, an armature assembly, a winding in said armature assembly subject to the field produced by said field magnet structure, a plurality of brushe for extending a connection from said armature assembly, an insulated pole piece-commutator member in said assembly providing a flux path for said winding and connected to said winding for providing commutation, and an extension portion on said insulated pole piece-commutator member engaging said brushes for establishing a connection therewith.

10. In a dynamo-electric machine, a field magnet structure, an armature assembly, a winding in said armature assembly subject to the field produced by said magnet structure, a plurality of brushes for extending a connection from said armature assembly, a plurality of insulated pole piece-commutator members in said armature assembly providing a fiux path for said winding and connected to said winding for providing commutation, and a plurality of extension portions integrally formed with said pole piece-commutator members for establishing a connection therewith.

11. In a dynamo-electric machine, a hollow cylindrical field magnet structure, an armature assembly encompassed by said field structure, a plurality of brushes for extending a connection from said armature assembly, a winding in said armature assembly subject to the field produced by said field magnet structure, a plurality of insulated pole piece-commutator members in said armature assembly providing a flux path for said armature assembly and connected to said winding for providing commutation, a plurality of extension portions integrally formed with said pole piece-commutator members for engaging said brushes for establishing a connection therewith, and a conducting surface on each of said extension portions contacting said brushes to establish the connections.

12. In a dynamo-electric machine, a hollow cylindrical field magnet structure, an armature assembly encompassed by said field magnet structure, a winding in said armature assembly subject to the field produced by said field magnet structure, a plurality of brushes for extending a connection from said armature assembly, a plurality of insulated pole piece-commutator members in said armature assembly providing a fiux path for said armature assembly and connected to said winding for providing commutation, a plurality of extension portions integrally formed with said insulated pole piece-commutator members intermeshing for providing an encased assembly and engaging said brushes for establishing a connection therewith, a conducting surface on each of said extension portions contacting said brushes to establish the connections, and an external circuit connected to said armature assembly by the connection established by said brushes.

MAXWELL R. KRASNO.

References Cited in the flle of this patent 238,053 Switzerland Sept. 17, 1945 

